Known is the incorporation of substituted phenylene aromatic diester as an internal electron donor in olefin polymerization catalyst compositions. In particular, the internal electron donor, 5-tert-butyl-3-methyl-1,2-phenylene dibenzoate in Ziegler-Natta catalyst compositions, contributes to high catalyst activity and high selectivity during polymerization to produce propylene-based polymer with high isotacticity.
Given the perennial emergence of new applications for olefin-based polymers, the art recognizes the need for olefin-based polymers with improved and varied properties. Desirable would be Ziegler-Natta catalyst compositions for the production olefin-based polymers that exhibit high catalyst activity during polymerization and produce propylene-based polymers with high melt flow rate, high isotacticity, and/or high catalyst activity.